1. Field of the Invention
The present invention relates to a sealed body. Further, the present invention relates to a light-emitting module in which a light-emitting element is sealed. Furthermore, the present invention relates to a method of manufacturing the sealed body.
2. Description of the Related Art
There is a known technique in which an object is sealed in a sealed body so that characteristics of the object are prevented from being degraded due to impurities from the outside.
In the case where the heat resistance of the object sealed in the sealed body is low, the temperature in the sealing step is desirably low so that damage to the object is reduced. In general, an organic material such as a resin can be solidified or cured at lower temperature than an inorganic material such as ceramics or glass, and is more advantageous in lowering the temperature in the sealing step.
On the other hand, as for a material used for a sealant, the diffusion rate of impurities therein is preferably lower. In general, an inorganic material has lower density than an organic material and has low diffusion rate of substances; thus, an inorganic material is suitable for the sealant.
In order to achieve both reduction in temperature in the sealing step and improvement in sealing performance, a structure has been used in which a glass having a lower melting point than other inorganic materials is used for the sealant. Further, there is a known method in which a low-melting-point glass interposed between a pair of substrates (at least one of which is a light-transmitting substrate capable of transmitting a laser beam) is irradiated with the laser beam to be locally heated so that the pair of substrates is attached to each other. By such a method, a sealed body can be manufactured without damage to a low-heat-resistance object sealed in the sealed body (Patent Document 1).